Checkbox disappear when display suite is used

Hi,

I wanted to create a member og reference (as user_reference but restricted to the group member) with this module, but when I edit my group, usernames does not appear in the result view. I just have history, picture, ... and the checkbox.

So I try to use display_suite to set the view mode Entity Reference View Widget to access to the username field, but the check boxes are gone !

I tried to do a simple user_reference and it's same.
You know how I could do to display the username or is it a bug?

thanks for your work
Jo